DS21352L+ Maxim Integrated Products, DS21352L+ Datasheet - Page 97

• Manufacturer Part Number: DS21352L+
• Description: IC TXRX T1 1-CHIP 3.3V 100-LQFP
• Manufacturer: Maxim Integrated Products

Specifications of DS21352L+

• Function: Single-Chip Transceiver
• Interface: HDLC, T1
• Number Of Circuits: 1
• Voltage - Supply: 3.14 V ~ 3.47 V
• Current - Supply: 75mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 100-LQFP
• Includes: DSX-1 and CSU Line Build-Out Generator, HDLC Controller, In-Band Loop Code Generator and Detector
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power (watts): -

18. TRANSMIT TRANSPARENCY
Each of the 24 T1 channels in the transmit direction of the framer can be either forced to be transparent or
in other words, can be forced to stop Bit 7 Stuffing and/or Robbed Signaling from overwriting the data in
the channels. Transparency can be invoked on a channel by channel basis by properly setting the TTR1,
TTR2, and TTR3 registers.
TTR1/TTR2/TTR3: TRANSMIT TRANSPARENCY REGISTER (Address=39 to
3B Hex)
Each of the bit position in the Transmit Transparency Registers (TTR1/TTR2/TTR3) represent a DS0
channel in the outgoing frame. When these bits are set to a one, the corresponding channel is transparent
(or clear). If a DS0 is programmed to be clear, no robbed bit signaling will be inserted nor will the
channel have Bit 7 stuffing performed. However, in the D4 framing mode, bit 2 will be overwritten by a
zero when a Yellow Alarm is transmitted. Also the user has the option to prevent the TTR registers from
determining which channels are to have Bit 7 stuffing performed. If the TCR2.0 and TCR1.3 bits are set
to one, then all 24 T1 channels will have Bit 7 stuffing performed on them regardless of how the TTR
registers are programmed. In this manner, the TTR registers are only affecting which channels are to have
robbed bit signaling inserted into them.
19. JTAG-BOUNDARY SCAN ARCHITECTURE AND TEST ACCESS PORT
19.1 DESCRIPTION
The DS21352/552 IEEE 1149.1 design supports the standard instruction codes SAMPLE/PRELOAD,
BYPASS, and EXTEST. Optional public instructions included are HIGHZ, CLAMP, and IDCODE. See
Figure 19-1. The DS21352/552 contains the following as required by IEEE 1149.1 Standard Test Access
Port and Boundary Scan Architecture.
Test Access Port (TAP)
TAP Controller
Instruction Register
Bypass Register
Boundary Scan Register
Device Identification Register
(MSB)
SYMBOLS
CH16
CH24
CH8
CH1-24
CH15
CH23
CH7
POSITIONS
TTR1.0-3.7
CH14
CH22
CH6
CH13
CH21
CH5
NAME AND DESCRIPTION
Transmit Transparency Registers.
0 = this DS0 channel is not transparent
1 = this DS0 channel is transparent
CH12
CH20
CH4
97 of 137
CH11
CH19
CH3
CH10
CH18
CH2
(LSB)
CH17
CH1
CH9
TTR2 (3A)
TTR3 (3B)
TTR1 (39)